Istanbul Bosphorus Turns Turquoise After Rain, Leaving Onlookers Mesmerized

Istanbul continues to host unique landscapes in every season with its historical and natural beauties. When natural phenomena are added to this beauty, images that rival fairy-tale scenes emerge. As you may know, the weather in Istanbul was rainy. The massive color change in the Bosphorus waters following the heavy rains provided a visual feast for the city's residents.

Following the heavy rains on September 30, the color of the Bosphorus turned turquoise. The unique view of the Bosphorus, with the influence of turquoise, was enveloped in an entirely different atmosphere.

The mechanism behind such color changes is generally the same. Intense rainfall transports fine sediments rich in calcium carbonate from surrounding river beds and slopes into the sea. As long as these sediments remain suspended in the water, they reflect and scatter sunlight differently. Consequently, the water takes on a lighter, milky turquoise hue, rather than its usual deep teal. The same effect is observed in the characteristic turquoise color of glacial lakes.

This color change is not permanent. As the sediments gradually settle to the bottom or disperse with the current, the water reverts to its original color within a few days. However, this effect, particularly when captured alongside cityscapes, creates a striking contrast. The sight of ferries and ships gliding on a turquoise backdrop further enhances the enchanting spectacle.